Apparatus for regeneration of ion exchangers



Jan. 16, 1951 w, 1 HUGHES 2,538,418

APPARATUS FOR REGNERATION OF ION EXCHANGERS Filed Nov. 21, 1946 2 Sheets-Sheet 1 Jan." 16, 1 9'51 w, J, HUGHESI 2,538,418

APPARATUS FOR REGENERATION 0F ION EXCHANGERS Filed Nov. 21, 194e l 2 sheets-sheet 2 f;

' 4; INVENTOR. 6 BYWaZzerJ//gz C zu Patented Jan. 16, 1951 APPARATUS FOR REGENERA'IIION 0F ION EXCHANGERS Walter J. Hughes, Chicago, Ill., assigner to Inlllco Incorporated, Chicago, Ill., a corporation of Delaware Application November 21, 194s, serial 10.711.424

(ci. 21o-24) 6 Claims.

Another object is an automatic zeolite softening system including automatically controlled meansxfor brining and recovery of brine.

lAnother-and principal object of the invention is a single measuring tank for regenerant recovery, wherein measured quantities of partly used regenerant and of fresh regenerant are received and stored, to be withdrawn separately and sequentially for use in a subsequent regeneration cycle.

Another object is to provide a single brine tank, means operative for introducing thereinto without intermingling, both partly used brine andfresh saturated brine for storage therein and means operative for withdrawing Ifirst the partly used brine land thereafter the fresh brine for use in anew regeneration cycle.

`Another object is to provide meansfor auto-.30

matically operating the means for brining, rinsing A to recovery and refilling of the brine tank..

Other objects of the invention will become apparentupon consideration of the description and claims-which follow.

In the regeneration of ion exchangers it has been found that there is a considerable diilerence between the quantity of regenerant actually used.- in regeneration to a given exchange capac/ity and the theoretical quantity of regenerant needed to satisfy the exchange equation. Thus in the regeneration of a zeolite softener, for instance; by a -brine containing common salt (NaCl), about V; pound NaCl theoretically satisfies the exchange for 1000 grains as CaCOa exchange capacity, while the quantity actually used is generally about 1/2 pound.

' In the regeneration of zeolite water softeners A by aV brine containing common salt it has been suggested recovering brine used in one regeneration cycle and reusing it in a subsequent regeneration, supplemented by a reduced quantity of fresh brine. This recovery method of regeneration peri mits substanti-al savings in salt used for regeneration. Instead of about the half pound of salt per 1000 grains of CaCOs exchange capacity commonly used in ordinary regeneration without recovery of brine, only about three tenths pound is needed when partly spent brine is recovered and reused. The saving thus amounts to about 40%. Obviously similar savings could be had in the regeneration of other exchangers, as for example the regeneration of carbonaceous zeolites by sulfurie acid, or the regeneration with caustic of duerme removal bodies, such vas those disclosed in Patent No. 2,227,432. Therefore, while my invention will be described for purposes of exemplication and illustration as applied to a zeolite softening system using brine as a, regenerant, for which it is especially well fitted, it is not limited to this application. Theinvention is useful in any system of regeneration where a marked difference between the theoretically needed and the actually used quantity of regenerant exists and in which there is a suitable difference in the specific gravity voi' the fresh and the re-used"` regenerant.

In carrying out recovery regeneration of zeolite softeners it has been usual to employ two brine tanks, one for the partly used and recovered brine and one for the freshly saturated brine. The use of two brine tanks involves also duplication of piping and valves and requires additional space and is therefore necessarily rela, tively expensive. Furthermore the operation of such a system is complicated and is not easily adapted to automatic control.

I therefore now propose to use a single. tank n for the fresh and the partly used brine, and to provide means whereby measured quantities of the two kinds .of brine are introduced into the single tank and remain separate therein and can be withdrawn to a softener in the desired se.

quence. E

I also provide means whereby the reused brine is wasted and only the brine used for the first time is recovered for a second use. My system, can be operated manually, but it lends itseli. readily to automatic operation and suitablel means for such automatic operation form a part of this invention.

In carrying out my invention I take advantage of the difference in weight between a saturated fresh and a diluted reused brine solution. Fresh saturated brine contains about 26% by weight of salt. On its way to use in the regeneration of the softener the fresh brine (in my apparatus andl process) is diluted to about 13%. This 13% brine is recovered and introduced into the bottom of my brine tank. When at the end of the recovery rinse saturated brine is admitted into the b ottom of the brine tank the heavier 26% fresh brine from the saturator displaccs the lighter recovered brine upwardly without any substantial intermingling of the two. The inlet means provided for my brine tank minimizes any intermingling and promotes stratification. Similarly I provide suitable take-off means which separately withdraws first the dilute brine and thereafter the fresh brine. I also provide means whereby the sequential operations of brine de-` livery to the softener, rinsing to waste, rinsing to recovery and refilling the brine tank with measured quantities of partly used and of fresh brine may be controlled automatically.

The invention will be more clearly understood by reference to the detailed description and to the drawings which form a part hereof and wherein:

Figure l shows diagrammatically a zcolite softening plant utilizing my invention Figures 2, 3 and 4 show diagrammatically means for automatically controlling the operations of brining, rinsing to recovery and refilling of the brine tank, Figure 2 showing the position of the various contacts as it exists immediately after termination of backwashing and at the start of brine delivery; Figure 3 the position after completion of brine delivery and at the start of brine recovery: and Figure 4 the position at the completion of the recovery operation: and

Figure 5 is a detail view diagrammatically lllustrating the contacts in the position switch, for controlling certain operations of the apparatus of my invention.

A softening plant utilizing my invention may include a softener I8, a brine measuring tank 48 and a saturator 38, interconnected by suitable conduits as described below. I prefer that the softener I be of conventional design, as shown, and contain a bed of zeolites I8. Preferably the softener tank contains a suitable underdrain system, not shown, as is well known in the art. Water to be softened is admitted under suitablel operating pressure through an inlet pipe I I, connected through an inlet valve I2 .anda branch pine I3 to thetop of the tank I8 for downow of the water through the bed of zeolites I8 during the softening run. Pipe II is also connected to the underdrain at the bottom of the tank I8, as through a wash water valve I4 and a branch pipe I5 for admission of wash water for upiiow through the bed I8 during backwashing. Softened water is withdrawn through a soft water conduit I8 provided with an outlet valve I1 which is also connected to pipe I5 which leads to the underdrain system. Washwater is withdrawn from above the bed I8 through pipe I3, a waste valve 28 and a waste conduit 2| discharging into a drain 22. A rinse conduit leads from the underdrain to the drain 22 and is provided with a rinse valve 28 and a recovery valve 21, the latter being normally open.

The saturator 38 is of conventional design and is shown as an open tank fitted with an underdrain draw olf pipe 3|. A layer of gravel 32 will usually be arranged over the pipe 3I to support the salt 33 with which the tank is fllled. Water is supplied to the saturator 38 through a supply conduit 34 which branches from inlet conduit I I. A normally open, emergency shut on' valve 35 may be provided on supply conduit 34 to permit shutting oil' the supplyof water to the saturator independently of the liquid level therein. Normally, however, the supply to saturator 38 through conduit 34 is controlled by a valve 36 operated by. a float 31 in a float compartment 38 communicating with theinterior of saturator 38 through an opening 38. The float 31 is set to close the valve 38 when the liquid level has reached a predetermined elevation, such as that shown in Figure l. The salt 33 dissolves in the liquid and forms a saturated brine of a density of 26% by weight, which lls the voids in the gravel 32 and is always available for draw ofi through underdrain draw oil pipe 3|.

Pipe 3| is connected to a brine transfer con duit 4I, provided with a valve 42. and thence to the brine measuring tank 48 through a suitable connection, such as T 43 leading into the bottom thereof. Also joined to the T connection 43 is a recovery conduit 44 which branches from the rinse conduit 25 at a point between the rinse valve 26 and the recovery valve 21. Preferably the recovery conduit 44 is provided with a check valve 45, however, in certain cases to be described below, the valve 45 may be a Isolenoid operated valve. The discharge end of the connection 43 is covered by a diffusor plate 48, as shown. Brine measuring tank 48 may be an open tank, as shown.

A jet pump or ejector 58 is located adjacent the brine tank 48 and receives water from supply conduit 34 through a branch conduit 5I. Flow through the branch conduit 34 is controlled by means of a suitable ejector valve 52. The suction port of the ejector 58 communicates with the brine tank 48, preferably through a flexible connection, such as a hose 53. The decanting end of suction hose 53 may be carried by a float 54 provided with a spaced cover plate 55 at the bottom serving as a horizontal take off which prevents vertical currents to the suction opening. By this means I am enabled to withdraw the brines of different specific gravity separately and Without any mixing by vertical currents.` The discharge end of the jet pump 58 is connected to the softener I8 by a conduit 58 provided with a l suitable brine inlet valve 51.

Figure l shows the brine tank 48 ready for use, filled to a given level with measured quantities of partly used brine, indicated by the vertical broken lines, 'superposed upon and stratified across saturated fresh brine, indicated by the horizontal broken lines. The charge of partly used, or 13%, brine is about twice the volume of the saturated, or 26%, brine. The size of tank 48 will be figured on the basis of three tenth pound salt equivalent for each 1000 grains of CaCO? exchange capacity of the softener. Since saturated brine at atmospheric pressure contains about 2.6 pounds of salt per gallon, the volume of fresh saturated brine required for regeneration of any particular softener can be readily determined. The brine tank 48 should have a holding capacity of 3 times the volume of saturated brine required, since there will be about two volumes of partly used brine recovered.

The operation of the zeolite softener I8 during softening and backwashing is conventional and need not be described in detail. During softening all valves will be closed with the exception of inlet valve I2, outlet valve I1 and the normally open valves 21 and 35, the position of valve 36 depending on the liquid level in saturator tank 38. Water to be softened will be admitted through pipe II and branch pipe I3 to the top of the tank I8 and now downwardly through the zeolite bed I8 to be withdrawn to a point of use or further treatment through soft water conduit I6. When the exchange capacity of the bed I8 is exhausted inlet valve I2 and outlet valve I1 are closed and wash water valve I4 and waste valve 28 are opened and the wash water is admitted through pipe I I and branch pipe l5 to the atadas 8 bottom of the tank I hence it flows upwardly through the bed. to be withdrawn from above the bed through waste conduit 2| into drain 22. all as usual in the art.

When backwashing is finished, wash water valve I4 and waste valve 20 are closed and elector valve 62, brine inlet valve 61 and rinsevalve 26 are opened; brine transfer valve 42 being closed at this stage. Brine is then eiected by ejector 60 from brine tank 40 through the floating decanting take off 65 and flexible connection 63 and is vdelivered through conduit 66 into the top of the softener I0 whence it is forced downwardly `through the bed I8 through a suitable distribution means, not shown. The floating take oii delivers4 first the 13% brine from the `upper portion of the brine tank, and thereafter the 26% brine, until all brine (both the recovered and the fresh) has been ejected from brine measure tank 40.v The ejector is of such construction that the A'Jet water and brine are mixed in the ratio of .about 1 to 1.

y. Thus the partly used brine is diluted from 13% ,to about 61/20/71, while the vsaturated brine is diluted from 26% to about .13%. j The free board space of the softener I0 and the voids between particles of the zeolite are sufiicient to hold practically all of this volume. I'he water within these spaces, introduced previously to briring, is displaced downwardly and out through the onen valves 26 and 21 to waste. When all brine has been ejected eiector valve 62 and brine inlet valve 51 are clsed and the inlet valve I2 is opened to admit rinse water to the top of the bed to displace the brine and rinse the bed. The first brine being displaced is -the 61/2'% brine which has been used for the second time. This is allowed to go to waste through the open valves 26 and 21. But as soon as this 6%% brine has been expelled and the new 13% brine begins to emerge' the recovery valve 21 is closed. thus diverting this brine through recovery conduit 44. check valve 45 and connection 43 into the brine tank 40. When the two volumes of 13% brine have been recovered, recovery valve 21 is reopenedV Inlet valve |2 having been opened after the termination of the brine delivery operation to admit rinse water to the top oi.' the softener I0 to displace the brine and rinse the bed downwardly, the reopening of valve 21 permits completion of the rinse through conduit 26 and the open valves 26 and 21 to drain 22. When this rinsing operation is finished the rinse valve 26 is closed. the outlet valve I1 opened and the softening evcle starts again.

After recovery of the two volumes of 13% brine is completed valve 42 is opened and one volume of fresh or saturated, 26%. brine runs-into the brine tank 40 from saturator tank 30 through draw on.' pine 3|, brine conduit 4| and connection 43, the one volume being measured by restoration of the levels in measuring tank 40 and saturator tank as controlled by the float 01. The diii'usor plate 46 distributes the incoming heavy brine horizontally across the tank so that it stratifies below the lighter Partly used brine which isL displaced upwardly without intermingling with the saturated brine. When the proper measure of saturated brine has been transferred to brine measuring tank the valfe 42 ls closed and the brine tank is now ready for reuse when a new regeneration of the softener is needed.

The operations of brine delivery to the softener l0, of recovery rinsing and of admitting of saturated brine to the brine measuring tank 40 may be carried out manually by settingV the valves in the sequence and manner described above. However, they also may, and usually will be carried out automatically in cyclic sequence and as functions of an automatic time cycle used in the operation of the softener. Figures 2. 3 and 4 show diagrammatically suitable means for carrying out such automatic operations.

The softening and backwashing may be automatically controlled in a usual manner by a position switch |02 which may be of a well known construction such as a micro switch operated by a rotatable cam |01, from a timer |00 driven by a timer motor. I0|. 'Ihe position switch |02 controis operation of the inlet and outlet valves, the wash water and waste valves and the rinse valve of the softener in proper sequence and in any suitable manner, such as for instance by hydraulic means. Suchn'eans and operation are well known in the art and are not shown and brine measuring tank 40 are fitted into the conventional cycle of such operations. These means may include two floats, 60 and 6|. which are operated by changes in the liquid level in brine tank 40. Rod 62 of fioat 60 carries collars 63 and 64, and rod 65 of float 6| carries collars 66 and 61. Two double-throw double-pole switches, 68 and 68, are in a separate circuit across the power circuit Li-Ia to the timer |00 and are positioned so as to be operated by the col1ars63 and 64, and 66 and 61, respectively. The relative position of the collars 63 and 64 on rod 62 and of switch 68 is such that float 6|! rides on the liquid surface when the tank is full, and is permitted to descend to adjacent the bottom of the tank when all brine has been ejected, the lower collar 63 tipping switch 68 when the oat is in its uppermost position and the upper collar 64 reversing the switch when the ficat is in its lowermost position. T'he relative position of the collars 66 and 61 on rod 65 of float 6I and of switch 69 is such that the upward travel of fioat 6| is limited to the elevation where the brine tank is two-thirds full (when brine recovery is terminated), in which position the lower collar 66 tips switch 69. The downward extent of the travel of fioat 6| is not sharply critical and the two collars 66 and 61 can be quite close together, as shown.

I also provide two additional sets of contacts. 10 and 1 I, which are positioned by the cam |01 of the position switch |02 which also controls operation of the valves of the softener. For

clarity and simplification the contacts 10 and 1| are shown in Figures 2 to 4 of the drawings as separate from the position switch; it will be understood, however, that they form actually a part of the switch, as clearly shown in the diagrammatic illustration of the position switch |02 shown in Figure 5. In this figure the contacts 10 and 1| of the switch are shown as being alternately closed by a contact arm |03, operated by a plunger |04. The plunger I 04 is slidably mounted in the frame for the switch and engages the contact arm |03 at one of its ends and a follower arm |05 at its opposite end. The contact arm I 03 may be secured to the frame of the switch at one of its ends and may be made of an elastic material such as phosphor bronze or spring steel, so as to follow the plunger upon .its return path. The follower arm |05 may be secured to 7 the outside of the frame of the switch at one of its ends and may have a cam follower, such as a roller |08 at its opposite end. The follower arm |88 may also be made of an elastic material such as spring steel, to hold the roller to the face of the rotatable cam |01. The timer is set to actuate position switch |02 to close contact 10 immediately after termination of backwashing.

At this time, as shown in Figure 2,- the float 80 is at its highest point of travel and collar 80 'has tipped the switch 88 to the position to close contacts 12 and open contacts 18. Closing of contact establishes, therefore, a circuit from source of power L1 through conductors I i0 and I, contact 10, conductor ||2, contacts 12 of oat switch 80. conductors ||3 and ||4 to solenoid 10 of ejector valve 82 and thence through conductor IIB and conductor to source of power La. Closing of this circuit energizes also solenoid 14 ofbrine inlet valve 51 which is connected to this circuit through conductors ||8 and ll1. This opens valves 52 and 51. Rinse valve 28 is controlled by the timer |00 in usual manner to be opened 'hydraulically by position switch |02 immediately after the backwashing operation is concluded,

A which coincides with the closing of contact 10 by position switch |02.n Valves 82, 81 and 28 now being open, brine delivery starts and brine is ejected from brine tank 40 and delivered to the top of softener l0 and is forced through the zeolite bed to be discharged to drain 22.

I also provide a relay 80 whose coil 8| is connected in the circuit through contact 10 and contact 12 ofswitch 88, above described. Closing of contact 10 by position switch |02 establishes therefore also a circuit from L1 through conductors ||0 and contact 10, conductor ||2, contacts 12, conductors H3, and H8, coil 0| of the normally closed relay 80, and conductors ||8 and |20 to La. Prior to the closing of contact 10, the pole 82 of relay 80 is in closed position and a circuit is' closed from L1 through conductors ||0 and |2|, timer motor |0|, conductor |22, pole 02 of relay 80, binding post 80 of relay 80 and conductor |23 to La. However, when contact 10 is closed and the coil 8| of relay 80 is energized, as above described, the pole 82 of relay 00 opens. This breaks the circuit to the timer motor |0| and the timer |00 is thereby stopped. The timer remains stopped as long as coil 8| is energized, or, in other words, as long as the circuit through contacts 10 and 12 is closed, which is coextensive with the period of travel of float 80 from its highest position to its lowermost position, i. e. with the period of brine delivery from brine tank 40 to softener |0. When at the end of the brine delivery the oat 80 reaches its lowermost position in brine tank 40, collar 84 on oat rod 82 tips switch 88 from the position shown in Figure 2 to that shown in Figure 3, whereby contacts 12 of switch 88 are opened and contacts 18 are closed. This breaks the circuit to solenoid 14 of ejector valve 52 and solenoid 14 of brine inlet valve 81 at 12 so that these solenoids are deenergized and the valves 52 and 81 closed. Breaking of the circuit at contact 12 also .deenergizes coil 8| of relay 80 to close the pole 82 whereby the circuit to the timer motor is again closed and the timer |00 is restarted. The timer will thus be idle during the volumetric operation of brine ejection and delivery and restart operation when brine delivery has been completed and valves 52 and 51 have been closed.

Before float 80 reaches the position wherein collar 84 tips float switch 80 the float 8| will have lib 8 reached the position wherein collar 81 tips switch 88 from the position shown in Figure 2 (where .contacts 18 are closed and contacts 18 open) to` the position shown in Figure 3, where contacts 10 are closed and contacts 18 are open.

When the timer |00 is restarted. it starts the rinse operation in the usual manner by cotrolling position switch |02 to hydraulically open inlet valve I2. whereby rinse water is admitted to the top of the tank- I0. to displace and wash out the brine in the bed. The timer also is set to control position switch |02 to close contact 1| and open contact 10 at the time when theheavy 13% brine begins to be displaced and appear at the recovery valve 21. Closing of contact 1| completes a circuit from source of power L1 through conductors ||0, and |28, contact 1|, conductor |28, con tact-s 18 of switch 88. conductor |21 to solenoid 08 of recovery valve 21 and thence through conductors |28, ||0 and |20 back to source of power In to close recovery valve 21. With valve 21 closed the 13% brine flows through recovery conduit 44, check valve 48 and connection 40 into the brine measuring tank 40, where it is spread evenly over the cross sectional area of the tank by thc diffuser plate 48. Recovery valve 21 continues in its closed position until the two volumes of 13% brine have been recovered, at which time the float 8| has reached its upper position as determined by setting of collar 88 and switch 80 is tipped by the collar 88 to the position shown in Figure 4. In this position of the switch 08 contacts 18 are opened and contacts 10 closed. This breaks .the circuit through the solenoid 88 of recovery valve 21 at contacts 19 whereupon valve 21 opens permitting the rinse water which follows the brine through the bed. to be discharged to the drain 22.

Float switch 88 at this intermediate position of the float is not yet tipped by collar 80 on rod 82 so that contact 18 remains closed and contact 12 is still open. In this position of the contacts, shown in Figure 4, a circuit is established from source of power L1 through conductors ||0 and |30, contact 10 of switch 89, conductor lll,

contact 18 of switch 88, conductor |32 to solenoid 08 of valve 42 and thence through conductors |08 and |20 back to source of power L2, to open valve 42 and admit saturated fresh brine from saturator 30 to brine measure tank 40.

As soon as brine tank 40 is filled to the predetermined level, as established by setting of button 83 on rod 82, the collar 63 tips switch 80 from the position shown in Figures 3 and 4 to that of Figure 2, where contacts 18 are open and contacts 12 are closed, thereby breaking the circuit to solenoid 88 of valve 42 at contacts 18. This closes valve 42 and stops flow of brine from the saturator to the brine tank 40. The brine tank 40 is now filled and ready for use, and all circuits broken until such time when the timer again closes contact 10 at the beginning of a new brining operation.

It will be seen that I provide simple and eilicient means for automatically controlling recovery regeneration with my single brine tank and for fitting the automatic operation of brining and brine recovery into the conventional cycle of automatically controlled operations o'f a zeolite softener. However, I do not wish to limit myself to the exact embodiments shown and described above for exempliflcation and illustration, as obviously these may be varied in many respects without departing from the spirit and scope of the invention. Thus. while it is preferable to stop the timer during brining by the relay 80, as described, it shouldbe understood that this is not essential. The timer could be allowed torun during brining, provided the cams of the position switch were shaped suitably, and this would permit elimination of the relay 00. Similarly, instead of controlling the rinse and recovery operations by using the three valves a's shown and described, the same effect could obviously be had by using the valve 21 as rinse valve and the valve 45 as the solenoid operated recovery valve. This would permit ,eliminating valve 26. While it is preferred to have the rinse valve in its usual position to avoid any change in the conventional layout of the softener, such a change in location of the valves is contemplated as one of the forms in which the invention can be embodied. Other changes will be apparent to those skilled in the art.

It will also be understood that the regenerant tank and the automatic means for operating revgenerant delivery and recovery can Veasily be adapted to use in regeneration of ion exchangers other than zeolite.

Iq claim: s

1. In a brine recovery regeneration system for a zeolite softener the combination with said softener of a single brine measuring tank, an inlet into the bottom of said tank, conduit means leading from the bottom of said softener to said tank inlet, a drain connection leading from. said conduit means to waste, a. valve on said conduit means upstream of said drain connection, a check valve atea point on said conduit means between said drain connection and said tank inlet, a normally open valve on said 'drain connection, second conduit means connecting said inlet to a source of saturated brine, a valve on said second conduit means, an ejector, a connection from a source of liquid under pressure to said ejector, a valve on said connection to said ejector, a flexible suction means connected to said ejector, a float supporting the inlet end of said suction means and adapted to float on liquid in said tank, a' connection from the ejector discharge to the top of said softener, and a valve on said last mentioned connection.

2. The apparatus of claim 1 including also means operable to stratify liquid in said tank and prevent upward currents, said means including a diifusor plate above said bottom inlet and a cover plate below the inlet of said suction means.

3. The combination with a zeolite softener in- "lcluding a softening tank, valved inlet means for water to be softened, valved outlet means for softened water, valved wash water inlet and outlet means, and a rinse conduit leading from the bottom of said tank and having a rinse valve, and a saturator having a water inlet and a brine outlet, of a brine tank, an inlet into the bottom of said brine tank, a brine recovery conduit leading from a point on said rinse conduit downstream of said rinse valve to said brine tank inlet, a, check valve on said recovery conduit, a normally open valve on said rinse conduit downstream of said recovery conduit, a saturated brine conduit leading from said saturator outlet to said brine tank inlet, an ejector, a connection to said ejector from. a 'source of liquid under pressure, a valve on said connection, flexible suction means connected to said ejector, a float supporting the inlet end of said suction means and adapted to oat on liquid in said brine tank. a conduit leading from the discharge end of said ejector to the upper portion ofsaid softener, and a valve on said conduit.

4. A recovery regeneration system for an ion exchange apparatus comprising a regenerant tank, inlet means for partly used regenerant discharging into the bottom of said tank, valve means controlling flow through said inlet means, inlet means for fresh regenerant discharging into the bottom of said tank, second valve means controlling flow through said fresh regenerant inlet means, a float in said tank, an ejector, a flexible conduit having an inlet supported by said oat and an outlet joined to the suction inlet of said ejector, a pressure water inlet to said ejecr tor, third valve means associated with said ejector inlet, outlet means from said ejector, a fourth valve controlling flow through said outlet means, solenoids associated with said valves for opening and closing the same, a first circuit through the solenoids of said third and fourth valve, a power driven timer, contact means operated by said timer to close said first circuit to open said third and fourth valve, float controlled means f operative to open said first circuit and thereby close said third and fourth valve, a second circuit through the solenoid of said first valve, a third circuit through the solenoid of said second valve, second contact means controlled by said timer to close said second circuit upon opening of the first circuit to open said first valve, oat controlled means effective to open said second circuit e and close said first valve, and to simultaneously close said third circuit to open said fourth valve, and float controlled means effective to open said third circuit and close said fourth valve.

5. The apparatus of claim 4 including also relay means adapted to stop said timer upon closing of said first circuit and to restart said timer upon breaking of said flrst circuit.

6. A recovery regeneration system for an ion exchange apparatus having an inlet for regenerant and an outlet for regenerant, comprising a regenerant tank, inlet means for partly used regenerant discharging into the bottom of said tank and adapted to be connected to said regenerant outlet, valve means controlling dow through said inlet means, second inlet means for fresh regenerant discharging into the bottom of the tank and adapted to be connected to a source of fresh regenerant. second valve means controlling ow through said second inlet means, an ejector, flexible suction means connected to said ejector, a float in said tank supporting theinlet end of said suctionmeans, an inlet to said ejector adapted to be connected to a. source of liquid under pressure, a valve controlling flow through said ejector inlet, an outlet from said ejector adapted to be connected to the regenerant inlet of said ion exchanger, and a valve controlling flow through said ejector outlet.

WALTER. J. HUGHES.

REFERENCES CITED The following references are of record in the Tiger June 10, 1947 

1. IN A BRINE RECOVERY REGENERATION SYSTEM FOR A ZEOLITE SOFTENER THE COMBINATION WITH SAID SOFTENER OF A SINGLE BRINE MEASUREING TANK, AN INLET INTO THE BOTTOM OF SAID TANK, CONDUIT MEANS LEADING FROM THE BOTTOM OF SAID SOFTENER TO SAID TANK INLET, A DRAIN CONNECTION LEADING FROM SAID CONDUIT MEANS TO WASTE, A VALVE ON SAID CONDUIT MEANS UPSTREAM OF SAID DRAIN CONNECTION, A CHECK VALVE AT A POINT OF SAID CONDUIT MEANS BETWEEN SAID DRAIN CONNECTION SAID TANK INLET, A NORMALLY OPEN VALVE ON SAID DRAIN CONNECTION, SECOND CONDUIT MEANS CONNECTING SAID INLET TO A SOURCE OF SATURATED BRINE, A VALVE ON SAID SECOND CONDUIT MEANS, AN EJECTOR, A CONNECTION FROM A SOURCE OF LIQUID UNDER PRESSURE TO SAID EJECTOR, A VALVE ON SAID CONNECTION TO SAID EJECTOR, A FLEXIBLE SUCTION MEANS CONNECTED TO SAID EJECTOR, A FLOAT SUPPORTING THE INLET END OF SAID SUCTION MEANS AND ADAPTED TO FLOAT ON LIQUID IN SAID TANK, A CONNECTION FROM THE EJECTOR DISCHARGE TO THE TOP OF SAID SOFTENER, AND A VALVE ON SAID LAST MENTIONED CONNECTION. 